Brick packaging



Oct. 10, 1961 J. G. FELDKAMP ETAL 3,

BRICK PACKAGING Filed March 20, 1959 9 Sheets-Sheet 1 LLJ.)

l I l l Oct. 10, 1961 J. G. FELDKAMP ETAL 3,003,296

BRICK PACKAGING 9 SheetsSheet 2 Filed March 20, 1959 Oct. 10, 1961 J. G. FELDKAMP EI'AL 3,003,296

BRICK PACKAGING 9 Sheets-Sheet 3 Filed March 20, 1959 IIIT I 1 u l A9. 1 1 1 5 FQ U Oct. 10, 1961 J. G. FELDKAMP ETA]. 3,003,296

BRICK PACKAGING 9 Sheets-Sheet 4 Filed March 20, 1959 Oct. 10, 1961 J. G. FELDKAMP ETA]. 3,003,296

BRICK PACKAGING 9 Sheets-Sheet 5 Filed March 20, 1959 Oct. 10, 1961 J. G. FELDKAMP ETAL 3,003,296

BRICK PACKAGING 9 Sheets-Sheet 6 Filed March 20, 1959 Oct. 10, 1961 J. G. FELDKAMP ETAI. 3,003,296

BRICK PACKAGING 9 Sheets-Sheet 7 Filed March 20, 1959 Oct. 10, 1961 J. G. FELDKAMP EI'AL 3,003,296

BRICK PACKAGING Filed March 20, 1959 9 Sheets-Sheet 8 Oct. 10, 1961 J. G. FELDKAMP ETA]. 3,003,296

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PRESSURE SOURCE United States Patent 3,003,2% BRICK PACKAGING John G. Feldkamp, Homewood, and George H. Burt and Robert E. Hager, Park Forest, 111., assignors to Acme Steel Company, Chicago, 111., a corporation of Illinois Filed Mar. 20, 1959, Ser. No. 800,7 48 26 Claims. (Cl. 53-26) This invention generally relates to the art of strapping and particularly to the art of strapping or bundling stacks of units such as bricks or the like.

In recent years, efiort has been directed toward developing improved means for handling construction materials in order to lower the ever increasing labor and handling costs. Much of this effort has been applied to the handling of bricks since they are used in large quantities which makes cost savings in their handling significant.

A major step toward the efficient and economical handling of bricks has been the use of a unit pack of a plurality of bricks stacked in abutting parallel rows and encircled about its periphery with a single loop of metal strap which is tensioned tightly to hold the bricks together as a unit. At two locations in the pack, openings for the forks of a lift truck are provided by omitting a few of the bricks in a single horizontal row. Paper strips are prepositioned above and below the particular horizontal row to bridge and support bricks in adjacent horizontal rows and prevent them from shifting into the openings. In addition, before the metal strap is applied, paper or cardboard corner protectors are provided at the four corners of the unit pack about which the metal strap is positioned. These protectors prevent the strap from cutting into the corner bricks and damaging them and also prevent their damage when the pack is subsequently handled.

Although the unit pack of bricks, which ordinarily embodies one-hundred bricks, has proven very satisfactory for shipment to and handling by the brick user at the construction site, certain difiiculty has been encountered in providing adequate means for forming and strapping the unit packs. It is, therefore, an important object of this invention to provide improved means for efliciently, economically and expeditiously forming and strapping unit packs of brick. It is another object to provide such means which permits the forming and strapping of successive unit packs one after another continuously in assembly line manner. It is still another object to provide such means having indexing means which insures the proper centering of the metal straps applied to successive unit packs. Another object is the provision of the application of paper or cardboard corner protectors to the unit packs in a continuous manner automatically while indexing the unit packs and applying metal straps about them. Another object is the provision of the application of paper or cardboard corner protectors to the unit packs continuously while indexing the unit packs and applying metal straps about them, wherein the continuous lengths of the corner protectors held by the metal straps maintain the unit packs joined together successively as a single large integral group which can be quickly and easily separated into smaller integral groups of multiples of the unit packs as desired by severing the corner protectors where required for this purpose. For example, if it is convenient to handle five unit packs together, five of them are removed integrally without severing the corner protectors secured between them. Similarly, any other convenient integral number of unit packs can be handled together.

In order to effectuate these objectives, conveyor means is provided on which the bricks are conveniently stacked at one station with a sufiicient number and arrangement required for a unit pack. After the first stack is com- 3,003,296 Patented Oct. 10, 1961 ice pleted, another can be arranged behind it and, in this manner, any number of properly arranged stacks can be formed. Simultaneous with this operation, the first or leading stack can be fed forward to a second station where a metal strap is encircled about the stack and tensioned and sealed into a taut closed loop to hold the stack together as a unit pack. After the first stack is strapped, the next successive stacks can also be strapped in turn.

To insure the proper indexing of the stacks so that the metal straps are always strapped centrally of the stacks, a magnetic sensing means is employed which causes a braking action to arrest the travel of the stacks when the sensing means responds to the presence of the metal strap on the stack just strapped. This leaves the next stack at the strapping station ready for a strap. As the next stack is strapped, the cycle repeats for succeeding stacks.

The corner protector paper or cardboard is preferably supplied in strips continuously from rolls aligned to supply a strip to each longitudinal corner region of the stacks.

It is still another object of the invention to provide improved support means on which is mounted the strapping tool used to tension and join together the ends of the strap loops used to bind the brick stacks.

Other objects and advantages should become apparent upon reference to the accompanying drawings in which FIG. 1 shows a perspective view of an entire strapping machine used for applying corner protectors and strapping together unit packs of bricks;

FIG. 2 shows another perspective view of a portion of the machine of FIG. 1 except that the machine is shown at a three-quarter angle from its opposite end;

FIG. 3 shows a side elevation of the machine of FIGS. 1 and 2;

FIG. 4 shows a front end view of the same machine;

FIG. 4a shows a top plan view of the magnetic detecting unit used with the machine as viewed along the line 4a4a of FIG. 4;

FIG. 4b shows a sectional view of the strap feed mechanism as viewed along the line 4b4b of FIG. 4;

FIG. 5 shows a sectional view of the conveyor brake mechanism as viewed along the line 5-5 of FIG. 4;

FIG. 6 shows a sectional elevation through the strap guide portion of the machine as viewed along the line 66 of FIG. 3;

FIG. 7 shows a sectional view of the strap guide track as viewed along the line 77 of FIG. 6;

FIG. 8 shows a partial sectional view along the line 8-8 of FIG. 4;

FIG. 8a shows a sectional view along the line 8a8a of FIG. 8;

FIG. 9 shows a perspective view of a typical unit pack of bricks as packaged by the apparatus shown;

FIG. 10 shows a plan view of a coil of corner protector material and its holder and guide means as it would appear viewed along the line 1(i10 of FIG. 6;

FIG. 11 shows a side view of the corner protector material holding and guide means as viewed along the line 1111 of FIG. 10;

FIG. 12 shows a sectional view as viewed along the line 12-42 of FIG. 10;

FIG. 13 shows a sectional view as viewed along the line 13-43 of FIG. 10;

FIGS. 14 through 16 show schematic representations in top plan views of the machine of FIG. 1 in a series representing three different operating conditions of the strapping machine; and

FIG. 17 shows a schematic diagram of the electrical and pneumatic portions of the machine.

As viewed in FIG. 9, a typical unit pack 1 consists of a plurality of rows of stacked bricks 2. In the illustra- 3 tion shown, the unit pack contains one hundred bricks consisting of bricks stacked in thirteen rows of eight brick height except that two bricks are removed from two places in the second row level from the bottom of the pack. Where these bricks are removed there are square openings 3 and 4 into which the forks of a lift truck can be inserted to facilitate transporting the unit pack. In order to prevent downward shifting of the bricks immediately above the openings 3 and 4, a layer of heavy paper 5 is inserted above the second layer of bricks. To keep the bricks immediately below the openings 3 and 4 from shifting, another layer of paper 6 is positioned immediately above the first iayer of bricks. Other sheets 7 can be positioned between the other layers of bricks,'but it is not essential to do so. In order to protect the four corners of the pack about which a binder strap 8 is positioned, heavy. paper or cardboard corner protectors 9 are provided at each of the four corners. These protectors are bent at right angles to fit around each of the corners. After they are applied, a length of strap 8 is encircled about the unit pack into a closed loop and the two ends of the strap are joined together in overlapping relationship with an interlocked seal at 10 by a conventional sealing tool. The sealing tool preferably tensions the strap 8 prior to sealing it. After the strap 8 is applied, the unit pack of bricks is as shown in FIG. 9 and is a unitized package of bricks which can be moved about as a unit prior to removing the strap 8 and using the bricks.

A preferred embodiment of the brick strapping machine 11 of this invention consists of a frame 12 which is supported on legs 13, 14 and 15 and which supports a plurality of conveyor rollers 16 extending transversely of the frame and journalled at their ends in two side walls 17 and 18 which are in the form of angle iron. The rollers 16 are journalled so that they ordinarily freely rotate. At about the mid region of the frame 12 and at the far side of the machine is mounted a tubular post 19 which is attached to the frame 12 by means of two U-shaped brackets 20. The post 19 extends vertically upward of the frame 12 and supports considerable structure as hereinafter described.

One of the members partially supported by the post 19 is a strap guide track 21 which is especially shown in FIGS. 6 and 7. This track extends at the front of the machine from a level above the level of the frame 12 and downward to the level of the frame 12 and transversely across the frame 12 below the level of the rollers 16. It then extends upwardly to the far side of the machine and halfway across its top where it connects at its inner end to the guides of the strap feed device 22. &1itable bracing members 23 and 24 are provided on opposite sides of the track to support it in position on the frame 12.

A cross sectional shape of track 21 as shown in FIG. 7 is channel shaped with two outwardly bulging side walls 25 and 2 6 which are connected to a back member 27. The entire track is composed of a flexible material such as rubber or plastic so that its side walls 25 and 26 are free to flex outwardly in the direction of the arrows 28 to positions indicated in dotted lines at 29. a The reason for this flexibility is first of all to permit the track to be bent into the approximate C-shape that it is in and also to permit removal of the strap 8 as it is being drawn into a tight loop around a pack of bricks. As the strap 8 is being removed the side walls 25 and 26 of the track spread apart to accommodate this movement. To prevent snagging of the strap as it is fed into the track, a polished metal strip 30 is positioned against the back member 27 of the track for its entire length; Then as the strap is fed endwise around the track, it ordinarily maintains contact with this backing stn'p 30 rather than with the side walls 25 and26. V

The strap feed unit 22 is positioned at the end of an arm 31 which is attached by means of two U-shaped clamps 32 to the post 19. The feed unit can be of a general type wherein a feed roll 33 and an idler roll 34 are provided between which the metal strap 8 is fed. Features of the feed mechanism are particularly shown in FIG. 4b. Extending from the rear of the arm 31 is a plate 35 below which is mounted an electric motor 36 by means of bolts 37. The motor 36 has secured to the end of its shaft a strap feed wheel 38 which is aligned to engage the upper surface of the metal strap 8 fed by it. Immediately below the feed wheel 38 is the idler Wheel 34 which is mounted to rotate freely. on the end of a shaft 35' which is secured in position by means of a nut 39 on the threaded inner end of the shaft 35'. The shaft 35 is mounted at the lower end of an arm 40 whose upper end is secured to a shaft 41 which is journalled in two brackets 42 secured to the arm 31 by means of bolts 43. A wound spring 44 is mounted around the shaft 41 and reacts against the arm 40 and a portion of the arm 31 to normally urge the arm 41 in a clockwise direction with the idler wheel 34 moved away from its strap feed position to a position as indicated by phantom linesv at 45. Also attached to the shaft 41 is another arm 46 whose outer end is. provided with an enlarged bulbous end 47 to enable an operator to conveniently manipulate the arm 46 to cause rotation of the shaft 41 against the pressure of the spring .44 to cause the idler wheel 34 to be moved into engaging position adjacent to the feed wheel 38 as indicated in solid outline'in FiG. 4b.

In operation, the strap 3 is inserted below the feed wheel 38. Then, the arm 46 is actuated to move the idler wheel 34 into contact with the lower surface of the strap 8. The operator maintains the idler wheel 34 in this position as long as he desires the strap to be fed since release of the idler wheel 34 interrupts the strap feed. Although the motor 36 can be made reversibie in order to feed strap in both directions, it is only essential that it rotate in one direction and thereby feed the strap around the track 21, starting at the top of the track, in order to fill the track with strap as indicated in FIG. 6. After the track is filled, the.operator withdraws the strap out of the track and also away from the feed mechanism. Movement of the idler wheel 34 away from the feed wheel 38 permits this withdrawal of the strap.

Prior to applying a length of strap 8, the corner protectors 9 must be applied to the four corners of the unit pack of bricks next to be strapped. The corner protectors 9 are provided continuously from a single strip of cardboard or paper provided from coils 9a, 9b, 9c, 9d positioned adjacent each of the four corners. The coil 9a is mounted on a post 48 secured on a plate 49 supported on two brackets 56 and 51 mounted at their lower ends 59a and 51a to the frame 12. The upper ends of these brackets 50 and 51 extend ofl in a 45 degree angle so that the plate 4-9 and the coil 9a mounted thereon arepositioned at a 45 degree angle with the horizontal. Similarly, coil 9b is mounted on a post 52 which is mounted on a plate 53 extending at a 45 degree angle which in turn is secured to two brackets 54 and 55 whose lower ends 54a and 55a are secured to the frame 12. The coils 9c and 9d are suspended on shafts 56 and 57 mounted in depending brackets 58 and 59, respectively, which are supported by the frame 12.

As best shown in FIGS. 10 through 13, the leading end of the corner protector material 9 is led through a channel shaped guide 60 which is mounted to the plate 53 by means of two angle brackets 61 and 62 by means of bolts 63 and 64. The first portion 60a of the guide 60 is curved uniformly to redirect the corner protector strap approximately degrees after it leaves the coil 9b. The corner protector material then passes through another poriiOI! 60b of the guide 60 which is progressively bent toward its end 600 from a fiat cross sectional shape to a right angle shape in cross section. The strip or material 9 emerges from the end 600 of the portion 6011 with a right angle bend corresponding to that of the portion 600. The basic channel shape of the portion 60a is achieved by reverse bending its margins 60d. These margins 60d follow through to the portion 60b to its very end and these margins 60d retain the strip 9 within the entire guide 60. With the strip 9 projecting from the end 600 of the guide 60 with a right angle bend, it corresponds to the right angle shape of the corner of a unit pack of bricls along which it extends during the operation of the machine.

The coil 9a of strip material 9 is mounted on the plate 49 and on the post 48 in a manner identical to that of the coil 9b on the post 52 and the plate 53, except that everything is of the opposite hand. Similarly, a guide 65 of the opposite hand to guide 60 is provided. The guide 65 is the full equivalent of the guide 60 except that it is of opposite hand. This guide 65 guides the corner protector strip 9 from the coil 9a onto the other top corners of the unit packs of bricks packaged or strapped by the machine.

As best shown in FIGS. 8 and 8a, the strip 9 unwound from the coil 9c passes through a channel shaped guide 66 which is mounted by means of brackets 67 and bolts 63 to the frame 12. The channel shape of the guide 66 is achieved by reverse folding its margins 66a. The strip 9 passes through this guide 66 which directs it upward and around one of the conveyor rolls 16 and in line with the path of a lower corner of the unit packs of bricks which are fed along the conveyor. On the opposite side of the machine where the other coil 9d is mounted, another guide 69 is mounted on the frame 12 in a manner identical to that of the guide 66, but mounted with brackets on its opposite side since it is mounted on the opposite side of a frame member. However, the strip 9 from the coil 9c is guided through the guide 69 and up under the same roller 16 of the conveyor as the strip leading through the guide 66. This strip also emerges in line with the location of the path of the corners of unit packs of bricks as they are transported along the conveyor.

Secured at the approximate level of the feed unit 22 a plate 70 is secured to the post 19 by suitable U-shaped brackets 71. Pivoted at the rear of the plate 70 is the inner end 72 of an arm 73 which supports a strap ping tool 74. The inner end 72 is disposed in a tubular socket 75 secured to the plate 70. This permits the arm 73 to pivot in a horizontal plane about the socket. The other end 76 of the arm 73 is reversely bent into a U-shape and canies a sleeve 77 which is slidable back and forth along the U-shaped end 76. A coil spring 78 is telescoped on one leg of the U-shaped end 76 and it reacts against a fixed shoulder 79 on the arm 73 and the inner end 80 of the sleeve 77. This spring 78 thereby urges the sleeve 77 outward toward the extremity of the end 76.

The tool 74 carried by the arm 73 is actually carried directly by the sleeve 77. This mounting permits the operator to adjust the tool in and out along the arm 73 for convenience in positioning the tool appropriately. In addition, the arm 73 is provided with sufficient flexibility that the tool 74 can be raised or lowered a slight amount to accommodate variations in height of the stacks of bricks passing through the machine.

The particular strapping tool 74 indicated is one which can be powered in a conventional manner by means of pressurized air but it can just as well be any other conventional type strapping tool which, for example, is of a type similar to or the same as the one shown in US. Patent Number 2,536,536, issued January 2, 1951, to W. C. Childress and James M. Royal. This type of tool operates to both tension the strap 8 about the unit pack of bricks and also secures the two overlapping ends of the strap into an interlocking joint with an encircling tubular metal seal to provide a sealed joint of nearly the same strength as the strap itself. Many different types of joints are possible depending upon the particular tool used and this forms no part of the invention as such.

Secured by means of other U-shaped brackets 81 and 82 are two more plates 83 and 84. Secured to these plates 83 and 84 are two hinges 85 and 86 which are connected to a gate 87 to provide hinge supports for the gate. The gate 87 is approximately as wide as the frame 12 and can be pivoted between the positions shown in FIGS. 2 and 4, the FIG. 2 position being its open position which allows the unit packs of bricks to pass by it on the conveyor, and the FIG. 4 position being its closed position for blocking the passage of the bricks. At the outer end of the gate 87 is provided two sleeves 88 and 89 in which are mounted the opposite ends of a locking shaft 90. This locking shaft 90 is provided with two handles 91 and 92 which are connected to two blocks 91a and 92a, respectively, fixed on the locking shaft 90. The locking shaft 90 is free to be raised with a sliding movement in the sleeves 88 and 89, the handles 91 and 92 being provided to facilitate this movement. When the gate is in the open position as shown in FIG. 2, the locking shaft 90 is in its lowermost position and its end rests against a stop 93 secured to the frame 12. When the gate is closed to its position as shown in FIG. 4, the locking shaft 90 must be raised so that its lower end is carried over to the side 94 of a stop 95 which is secured to the frame 12. After the locking shaft 90 is positioned beyond the surface 94, it is released and it drops behind the surface 94, thereby preventing its return to an open position. In this position the gate resists the forward movement of the bricks which would be in the direction of the arrow 95a.

The purpose of the gate is to initially align the leading stack of bricks relative to the strap guide track 21 at the initiation of strapping with the machine, as hereinafter described.

Mounted by means of bolts 99 is a plate 98 on a plate 96 secured by means of two U-shaped brackets 97 to the post 19. Pivoted on studs 100 secured in the plate 98 are two links 101 which extend parallel to each other and are connected at their far ends by means of pivot pins 102 and 103 to an arm 104. The arm 104 supports a frame 105 at its outer end and this frame 105 carries a magnetic sensing head 106. The frame 105 carries a plate 107 at its forward end and this plate 107 is provided with bent ends 108 and 109 which are directed rearward angularly of the magnetic sensing head 106. The purpose of these ends 108 and 109 is to act as camming surfaces when the unit packs of bricks are moved forward on the conveyor to prevent snagging of the bricks on the frame 105 and insure proper alignment of the frame 105 and the magnetic sensing head 106 along the side surfaces of the bricks. It is apparent from the pivotal arrangement of the links 101 that the frame 105 is free to be moved transversely of the conveyor certain amounts as indicated generally by the positions indicated in bold outline and phantom outline in FIG. 4a. A coil spring 110 is connected between the stud 100 and the pivot pin 102 to constantly urge the frame 105 toward the conveyor. A stop pin 111 is mounted on the arm 104 to limit the movement of the frame 105 toward the conveyor.

Mounted beyond the strap guide track 21 and below the machine is a cylinder 112 which is provided with a piston 113 connected to a piston rod 114. The cylinder 112 has a flange 115 which is secured by bolts 116 to two angle brackets 117 and 118 secured to two frame members 119 and 120 of the frame 12. At the upper end of the piston rod 114 is a coupling 119 provided with a connecting pin 121 which secures a brake plate 122 to the piston rod 114. The brake plate 122 is provided with a suitable high friction material or brake lining 123 at its 7 t upper surface. This entire unit which is referred to as the brake 124 is actuated at a time when it is desired to halt movement of the brick stacks on the conveyor. Ordinarily, the piston 113 is retracted to hold the brake lining 123 away from the rollers 16 immediately above it. However, when it is desired to stop the movement of the bricks, the piston rod 114 is extended by admitting pressurized air or other fluid to the proper side of the cylinder 112 and this causes the brake lining 123 to contact the four conveyor rollers 16 immediately above the brake lining 123. This arrests the free rotation of the rollers 16 and thereby arrests the motion of the bricks above it on the conveyor. V

The operation of the entire machine is indicated in three basic steps in FIGS. 14, and 16. As shown in FIG. .14, the bricks 2 are stacked, as previously described, in unit packs 1 abutting each other one after the other. The leading pack of bricks is pushed forward until its leading surface 1a contacts the surface 87a of the gate 87 when the gate 87 is in its closed position extending at a right angle to the direction of travel of the unit packs of brick. In this position, the locking shaft 90 is engaged by the latch 95, as previously described, to maintain its closed position. The relationship of the closed position of the gate 87 with the position of the strapping tool 74 and the strap guide track 21 is such that the center line 8b of the strap when it is in the strap guide track 21 and aligned with the strapping tool 74 bisects the bricks of the leadingrunit pack 1. This insures that the strap 8 will be applied centrally of this leading unit pack. After this relationship is established, the gate 87 is opened by swinging it in a clockwise direction between its position shown in FIG. 14 to its position shown in FIG. 15. Either before or after this time, the strap 8 is fed through the strap guide track 21 as it is withdrawn from a suitable conventional unreeler 125 which supports a coil 126 of the metal strap 8. Several difierent types of unreelers are available on the market for this purpose and the :unreeler forms no part of this invention. Its sole purpose is to V supply to the machine a continuous length of strap 8 as required during its operation. In order to start the feeding of the strap around the strap guide track 21, the operator must feed the leading end 8a below the feed wheel 33 and engage the idler wheel 34 with the under side of the strap 8 by actuating the arm 46. The idler wheel 34 is held in engagement with the strap 8 until the strap guide track 21 is filled with a length of strap 8 from one end to the other as shown particularly in FIG. 6. After a sufiicient length has been fed, the arm 46 is released and the idler wheel 3 disengages the strap 8 because of the pressure of the spring 44 as previously described. Although the feed wheel 38 can be-rotated by energizing the motor 36 only at the same time that the idler wheel 34 engages the strap 8, it is preferred that the motor 36 be energized constantly so that the feed wheel '38 is rotating at all times during the operation of the machine, even between strapping cycles. Either before or after the strap is fed around to a positionjas indicated in FIG. 6, the corner protector material 7 must be fed to engage its leading ends from all of the coils 9a, 9b, 9c and 9d with the fourv longitudinal extending corners of the leading unit pack 1 of bricks.

At this time, the leading end of the strap 8a is inserted into the strapping tool 74 in a conventional manner and the supply end 80 is also inserted in the tool 74. Simultaneously with this, the strap 8 which is in the form of a loop shown in FIG. 6 is withdrawn from the strap guide track 21 merely by withdrawing the supply end 80. The next operation is that of the strapping tool which is used to shrink the loop of strap about the leading unit pack of bricks and tension it into a taut loop thereon. Further actuation of the tool joins together the leading end 8a and the supply end 80 with an interlocking type joint, preferably interlocked with an enclosed tubular metal seal. As previously stated, the strapping too1 74 can be of many difierent conventional types which may either be completely hand powered or actuated electrically, pneumatically or by hydraulic means. The particular tool shown is indicated as a type with pneumatic actuating means for its operation. An air motor 74a isused to power its tensioning means for tensioning the strap while an air cylinder 74b is used to actuate a joint forming means associated with the tool. Obviously a powered tool facilitates the strapping operation since it requires less effort on the part of the operator of the machine. 7 I

After the strap has been tensioned and sealed properly, it assumes the appearance of the unit pack shown in FIG. 9, except that the corner protector strips 9 are still connected to their supply coils 9a, 9b, 9c and 9d. It is important to note that the strap 8 which is securely held on the unit pack also tightly grips the corner protectors 9 and holds them in place.

The next step in the operation of the machine is to push forward the unit packs 1 of the bricks to new positions as indicated in FIG. 15. As soon as the strap 3, which is then encircling the leading unit pack 1, reaches alignment with the magnetic sensing head 106, an electricimpulse, as will hereinafter be described, causes air to enter the cylinder 112 of the brake 124- in a direction to cause the piston rod 114 to extend and apply the brake lining 123 to the four conveyor rollers 16 immediately above the brake lining 123. This arrests the movement of these four rollers 116 which in turn stops the movement of all of the bricks resting on the conveyor. Because of the spontaneous response of the brake 124, the leading unit pack 1 stops with its strap 8 located centrally of the magnetic sensing head 1&6. By having the center line of the sensing head spaced from the center line 8b of the strap path exactly equal to the width of the unit pack 1 which is equal to the length of each of the bricks of the pack, the bisector of the second unit pack 1 aligns with the center line 3b of the strap path through the strap guide track 21. This means that upon application of the strap 8 around the second unit pack in a manner identical to that as described for the first unit pack, the strap will be aligned centrally of the pack. When it is desired to again move the bricks forward, the brake 124 is released, as hereinafter described, to disengage the brake lining 123 from the four rollers 16 immediately above it. The operator then pushes the bricks forward until the third unit pack 1 is centrally aligned with the strap guide track 21. A strap is applied to the third unit pack by repeating the cycle just described, and thereafter to the subsequent packs following these first three. The general appearance of the relationship of the stacks at this time is indicated in FIG. 16. It is indicated in FIG. 1 after several more packs have been strapped.

One of the most important features of the invention is that the corner protector strips 9, after they have been manually applied to the first unit pack 1 and held in place a by the first loop of strap 3, need not be handled manually thereafter. As the bricks are moved forward, the corner protector strips 9 follow along the longitudinal corners of successive unit packs and are progressively secured in place as the subsequent strap loops are applied. For convenience in handling, it is oftentimes desirable to handle five unit packs 1 as an integral unit. This is conveniently done by placing the forks of a fork lift truck in the openings 3 and 4 extending through five of the unit packs at the end of the conveyor. As the five are lifted together by the forks of the truck, the corner protector strips 9 tear or shear oft" at the separation between the fifth and sixth unit packs. If the material'of the corner protector strips is too heavy to shear by itself evenly, the operator can cut them before the unit packs are lifted. In this manner, one, two, three or any other convenient number of unit packs can be handled integrally.

With reference to FIG. 17 which shows the electrical circuit and the pneumatic circuit for operating the machine, line voltage is supplied between the lines 127 and 128. When a main switch 129 is closed, the line voltage reaches the connections 130 and 131 on the strap feed motor 36 to cause it to rotate and start the rotation of the feed wheel 38. Assuming that the machine is being initiated in operation and that no unit packs of bricks have been strapped as yet, none of the other electrical portions of the machine are yet energized. The bricks are stacked into unit packs as described and the leading unit pack is brought to bear against the gate 87 in a manner as described and the first strap is applied to this leading unit pack 1. After the gate is opened, the bricks are moved forward as described and when the taut strap on the leading unit pack 1 comes into the vicinity of the magnetic sensing head, the metal strap is attracted by a small permanent magnet 106a within the magnetic sensing head which pulls the switch contactor 10617 to cause a switch 106:: in the magnetic in the magnetic sensing head to thereby energize a solenoid 132 of a spring return solenoid valve 133. This causes the valve 133 to internally position its ports in such a manner that air under pressure from a conventional source 134 is supplied to the air conduit 135 which leads to the piston side of the brake cylinder 112. Simultaneously, the conduit 136 from the piston rod side of the cylinder 112 is connected to an exhaust conduit 137 which is open to the atmosphere. This causes the piston 113 to extend and apply the brake lining 123 to stop the conveyor rolls 116 above it and thereby arrest movement of the bricks on the conveyor. Simultaneously with this actuation of the brake, solenoid 138 of a relay 139 is energized to cause a relay switch 140 to close. This relay switch 140 is a holding switch which keeps the brake energized after the switch 1060 of the magnetic sensing head is again open. After the first braking action, and after a second strap is applied to the next unit pack of bricks, the brake must be released in order to permit forward movement of the brick packs so that successive brick packs can be strapped. This is accomplished by means of a foot switch 141 which can be opened by depressing its actuating arm by means of foot pressure. This foot switch 141 is indicated at the front of the machine in FIGS. 1, 3 and 4. As the foot switch 141 is opened, this breaks the circuit with the solenoid 132 of the solenoid valve 133 whose spring return causes the internal ports of the valve to be altered so that the air pressure source 134 is connected to the conduit 136 and the conduit 135 is connected to the air outlet 137. This immediately causes the brake piston 113 to retract and enable the brick packs to be transported forward. Simultaneously with the opening of the foot switch, the relay switch 140 is also opened since the relay solenoid 138 is also deenergized when it opens. The relay switch is also of a spring return type. As the strap 8 adjacent the magnetic sensing head passes by it, the permanent magnet 106a no longer has the strap in its magnetic field. This causes the contactor 106k to open the switch 1060 because of its spring return. Thus, all parts are returned to their initial positions. As soon as the strap on the next strapped pack reaches the vicinity of the magnetic sensing head, the brake is again applied and the cycle is repeated with the assistance of the machine operator.

Only a single embodiment of the strapping apparatus has been shown. However, it is obvious that the strapping means embodied can be made with many modifications without departing from the true scope of the invention.

The entire operation can be made more automatic, forexample, by using a solenoid actuator for positioning of the idler wheel 34 and a limit switch can be positioned at the end 21a of the strap guide track 21 in order to automatically actuate the solenoid means to stop the feeding when the strap guide track is filled with strap. Also, it is easily possible to combine another foot switch for causing the actuation of the solenoid and, thus, the strap feed, as described. Similarly, the strap guide track 21 can be made in many different ways embodying different types of retaining means for temporarily retaining the strap in the strap guide track during the strap feeding time. Also, it is not essential that the brake be applied by using pneumatic means. Hydraulic means or electric solenoid means can be used with equal efficiency. Taking into consideration the wide latitude and variations as suggested, the invention is defined in the appending claims.

We claim:

1. The method of packaging objects comprising, stacking them in vertical stacks in a line one after the other with their longitudinally extending corners in alignment with each other, applying the leading end of a continuous corner protector strip extending from a continuous supply of corner protector strip along one of the longitudinally extending corners of a first stack, applying a strap around the first stack to secure the corner protector strip to the stack and to hold the stack together while the corner protector strip is still connected to said continuous supply, then transporting forward said first stack and the next stack behind it, said first stack pulling the continuous strip along with it as it is transported forward to cause the strip to be drawn oil from said continuous supply and applied continuously to a corner of the said next stack.

2. The method of packaging brick shaped objects comprising, piling them in vertical stacks and positioning the stacks in a row, so that certain corners of the stacks are aligned longitudinally of the row, applying the leading end of a flexible corner protector strip extending from a continuous supply of corner protector strip to a said longitudinally aligned corner of a first of said stacks, applying a strap around the first stack to secure the corner protector strip to the stack and to hold the stack together as a unit pack of said objects while the corner protector strip is still connected to said continuous supply, then transporting forward said first stack and the next stack of the row behind it, said first stack pulling the continuous corner protector strip along with it as it is transported for- Ward to cause the strip to be drawn ofi from said continuous supply and applied continuously to a longitudinally aligned corner of said next stack and bridge the two stacks.

3. The method of packaging brick shaped objects comprising, piling them in vertical stacks and positioning the stacks in a row so that certain corners of the stacks are aligned longitudinally of the row, applying the leading end of a flexible corner protector strip extending from a continuous supply of corner protector strip to a said longitudinally aligned corner of a first of said stacks, applying a strap around the first stack to secure the corner protector strip to the stack and to hold the stack together as a unit pack of said objects while the corner protector strip is still connected to said continuous supply, then transporting forward said first stack and the next stack of the row behind it, said first stack pulling the continuous corner protector strip along with it as it is transported forward to cause the strip to be drawn ofi from said continuous supply and applied continuously to a longitudinally aligned corner of said next stack and bridge the two stacks, applying a second strap around the said next stack to secure the corner protector strip to the stack and to hold the stack together, said corner protector strip then being held securely by both straps as a connector between said stacks.

4. The method of joining together packs of objects comprising aligning the packs in a row, apply the leading end of a continuous connector strip extending from a continuous supply of corner protector strip to a first of said packs and applying a strap around said first pack to secure the connector strip to it while the corner protector strip is still connected to said continuous supply, transporting said first pack and the next pack behind it forward, said first pack pulling the continuous connector strip along with it as it is transported to cause the connector strip to be drawn oil from said continuous supply and applied to said next pack, applying a second strap around the next pack to secure the connector strip to said next pack while the acetate ing a metal strap around the leading stack at the strapping.

station, transporting forward the plurality of stacks as a unit and magnetically sensing the presence of the strap on the leading stack as the next successive stack reaches strapping position, and braking the plurality of stacks to 12 V of the row, a strap guide track on said conveyor positioned to guide a length of strap about one of the stacks on said conveyor as the strap is fed .into the said strap guide track, strapping means adjacent said strap guide track for withdrawing the strap from the 'strap guide track and tensioning it into a closed loop about said stack,

a brakingmeans on the conveyor for arresting the move-,

ment of the stacks of objects on the conveyor, a magnetic sensing means for causing the braking means to be actuarrest movement of the said next stack at the strapping station in response to the magneticsensing.

6. The method of packaging comprising, positioning a plurality of two or more stacks of objects in a row with the leading stack located at a strapping station and the remaining stacks pushed up closely toward the leading stack with certain corners of all, of the stacks aligned longitudinally of the row, applying the leading end of a continuous corner protector strip to one of the longitudinally aligned corners of the leading stack, apply a metal strap around the leading stack at the strapping station to secure the corner protector strip to the stack and to hold the sack together, transporting forward the plurality of stacks as'a unit and magnetically sensing the presence of the strap on the leading stack as the next successive stack reaches strapping position, and braking the pluralityof stacks to arrest movement of the said successive stack at the strapping station in response to the magnetic sensing, said first stack pulling the corner protector strip along with it as it is transported forward to cause the strip to be applied continuously to a longitudinally aligned corner of said successive stack and bridge the two said stacks.

7. The method of packaging comprising, positioning a plurality of two or more stacks of objects in a row with the leading stack located at a strapping station and the remaining stacks pushed up closely toward the leading stack with certain corners of all of the stacks aligned longitudinally of the row, applying the leading end of a continuous corner protector stripto one of the longitudinally aligned corners of the leading stack, applying a metal strap around the leading stack at the strapping station to secure the corner protector strip to the stack and to hold the stack together, transporting forward the plurality of stacks as a unit and magnetically sensing the presence of the strap on the leading stack as the next successive stack reaches strapping position, and braking the plurality of stacks to arrest movement of the said successive stack at the strapping station in response to themagnetic sensing, sm'd first stack pulling the corner protector strip along with it as it is transported forward to cause the strip to be applied continuously to a. longitudinally aligned corner of said successive stack and bridge the two said stacks, applying a second metal strap around the said successive stack to secure the corner protector strip to the stack and to hold the stack together, said corner protector strip being held securely by both straps as a connector between said stacks.

8. A packaging machine comprising, conveyor means i for movably supporting a plurality of stacks of objects in.

a row, a strap guide track on said conveyor positioned to guide a length of strap about one of the stacks on said conveyor as the strap is fed into the strap guide track, strapping means adjacent the strap guide tracks for withdrawing the strap from the strap guide track and tensioning it into a closed loop about said stack, braking means on the conveyor for arresting the movement of the stacks on the conveyor, and magnetic sensing means for causing the braking means to be actuated in response to the presence of a strap on a strapped stack.

9. A packaging machine comprising, conveyor means for movably supporting a plurality of closely positioned stacks in a row extending along the length of the conveyor, said stacks all having the same dimension in the direction ated in response to the presence of a strap from a strapped stack, the magnetic sensing means being spaced forward of the strap guide track by an amount equal to said dimension of the stacks, said forward spacing of the magnetic sensing means insuring that the stack immediately following a stack just strapped is properly aligned for strapping adjacent the strap guide track when the braking occurs to magnetic sensing of the strap on the stack just strapped.

10. A packaging machine comprising, conveyor means for movably supporting a plurality of closely positioned stacks in a row extending about the length of the conveyor, said stacks all having the same dimension in the direction of the row, a strap guide track on said conveyor positioned to guide a length of strap about one of the stacks on said conveyor as the strap is fed into the said strap guide track, strapping means adjacent said strap guide track for Withdrawing the strap from the strap guide track and tensioning it into a closed loop about said stack, a braking means on the'conveyor for arresting the movement of the stacks of objects on the conveyor, a magnetic sensing means for causing the braking means to be actuated in response to the presence of a strap from a strapped stack, the magnetic sensing means being spaced forwardof the strap guide track by an amount equal to said dimension of the stacks, said forward spacing of the magnetic sensing means insuring that the stack immediately following a stack just strapped is properly aligned for strapping adjacent the strap guide track when the braking occurs due to magnetic sensing of the strap on the stack just strapped, said magnetic sensing means comprising a switch with a magnet which is magnetically attracted by and drawn toward a metal strap in its presence to thereby actuate the switch and electrically control the actuationof a solenoid operated valve in the switch circuit, said solenoid operated valve directing the flow of fluid to a fluid actuated piston connected to actuate said braking means. 7

11. A packaging machine comprising, conveyor means for movably supporting a plurality of stacks of objects in a row, a strap guide track on said conveyor positioned to guide a length of strap about one of the stacks on said conveyor as the strap is fed into the strap guide track, strapping means adjacent the strap guide track for withdrawing the, strap from the strap guide track and tensioning it into a closed loop about said stack, braking means on the conveyor for arresting the movement of the stacks on the conveyor, and magnetic sensing means for causing the braking means to be actuated in response to the presence of a strap on a strapped stack, said magnetic sensing means comprising a switch with a magnet which is magnetically attracted by and drawn toward a metal strap in its presence to thereby actuate the switch and electrically control the actuation of a solenoid operated valve in the switch circuit, said solenoid operated valve directing the flow of fluid to a fluid actuated piston connected to actuate said braking means.

12. A packaging machine comprising, conveyor means for movably supporting a plurality of stacks in a row extending along the length of the conveyor so that certain corners of the stacks are aligned longitudinally of the row, means for supporting a continuous supply of corner protector strip adjacent the conveyor, means for encircling binding straps about the vstacks successively to successively secure the corner protector strip to the stacks, said corner protector strip being pulled forward by at least one of the stacks to which it is secured as the stacks are moved forward along the conveyor, a guide adjacent the supply of corner protector strip for directing the strip and automatically causing it to be aligned with the said corners of successive stacks as it is pulled.

13. A packaging machine comprising, conveyor means for movably supporting a plurality of stacks of objects in a row, means on the conveyor for applying metal binder straps to each of the stacks, braking means for arresting the movement of the stacks as they are moved along the conveyor, and sensing means for causing the braking means to be actuated in response to the presence of a strap on a strapped stack.

14. A packaging machine comprising, conveyor means for movably supporting a plurality of stacks of objects in a row, means on the conveyor for applying metal binder straps to each of the stacks, braking means for arresting the movement of the stacks as they are moved along the conveyor, and magnetic sensing means for causing the braking means to be actuated in response to the presence of a strap on a strapped stack.

15. A packaging machine comprising, conveyor means for movably supporting a plurality of stacks in a row extending along the length of the conveyor so that certain corners of the stacks are aligned longitudinally of the row, means for supporting a continuous supply of corner protector strip adjacent the conveyor, means for encircling binding straps about the stacks successively to successively secure the corner protector strip to the stacks while the corner protector strip is still connected to said continuous supply, said corner protector strip being drawn off from said continuous supply and pulled forward by at least one of the stacks to which it is secured as the stacks are moved forward along the cn veyor.

16. A packaging machine comprising, conveyor means for movably supporting a plurality of stacks in a row extending along the length of the conveyor so that certain corners of the stacks are aligned longitudinally of the row, means for supporting a continuous supply of corner protector strip adjacent the conveyor, means for encircling bindertstraps about the stacks successively to successively secure the corner protectorstrip to the stacks, said corner protector strip being pulled forward by at least one of the stacks to which it is secured as the stacks are moved forward along the conveyor, braking means for arresting the movement of the stacks as they are moved along the conveyor, and magnetic sensing means for causing the braking means to be actuated in response to the presence of a strap on a strappedstack.

17. A packaging machine comprising, conveyor means for movably supporting a plurality of closely. positioned stacks in a row extending along the length of the conveyor, said stacks all having the same dimension in the direction of the row, astrap guide track on said conveyor positioned to guide a length of strap about one of the stacks on said conveyor as the strap is fed into the said strap guide track, strapping means adjacent said strap guide track for withdrawing the strap from the strap guide track and tensioning it into a closed loop about said stack, a braking means on the conveyor for arresting the movement of the stacks of objects on the conveyor, a magnetic sensing means for causing the braking means to be actuated in response to the presence of a strap from a strapped stack, the magnetic sensing means being spaced forward of the strap guide track by an amount equal to said dimension of the stacks, said forward spacing of the magnetic sensing means insuring that the stack immediately following a stack just strapped is properly aligned for strapping adjacent the strap guide track when the braking occurs due to magnetic sensing of the strap on the stack just strapped, a gate pivoted on said conveyor between a position blocking the forward passage of the stacks on the conveyor and a position clear of their passage, said gate in its blocking position being spaced from the strap guide track location by a fixed amount for the purpose of establishing the location of the first strap to be applied on the leading stack of the plurality of closely positioned stacks on the conveyor when they are all pushed up toward the gate with the leading stack in contact with it.

18. A packaging machine comprising, conveyor means for movably supporting a plurality of closely positioned stacks in a row extending along the length of the conveyor so that certain corners of the stacks are aligned longitudinally of the row, means for supporting a continuous supply of corner protector strip adjacent the conveyor, a strap guide track on said conveyor positioned to guide a length of strap about one of the stacks on said conveyor as the strap is fed into the said strap guide track, strapping means adj-acent said strap guide track for withdrawing the strap from the strap guide track and tensioning it into a closed loop about said stack to secure a portion of the corner protector strip to said stack, said corner protector strip thereafter being pulled forward by said stack as the stacks are moved forward together, a guide adjacent the supply of corner protector strip for directing the strip into alignment with corners of successive stacks as the stacks are moved forward together, braking means on the conveyor for arresting the movement of the stacks on the conveyor, a magnetic sensing means for causing the braking means to be actuated in response to the presence of a strap from a strapped stack, the magnetic sensing means being spaced forward of the strap guide track by an amount equal to said dimension of the stacks, said forward spacing of the magnetic sensing means insuring that the stack immediately following a stack just strapped is properly aligned for strapping adjacent the strap guide track when the braking occurs due to magnetic sensing of the strap on the stack just strapped.

19. A pack-aging machine comprising, conveyor means for movably supporting a plurality of stacks of objects in a row, a strap guide track on said conveyor positioned to guide a length of strap about one of the stacks on said conveyor as the strap is fed into the strap guide track, strapping means adjacent the strap guide track for withdrawing the strap from the strap guide track and tensioning it into a closed loop about said stack, braking means on the conveyor for arresting the movement of the stacks on the conveyor, and magnetic sensing means for causing the braking means to be actuated in response to the presence of a strap on a strapped stack, said magnetic sensing means being mounted on the conveyor for movement transversely of the conveyor in response to force applied by a strapped stack moving along the conveyor.

20. A packaging machine comprising, conveyor means for movably supporting a plurality of closely positioned stacks in a row extending along the length of the conveyor, said stacks all having the same dimension in the direction of the row, a strap guide track on said conveyor positioned to guide a length of strap about one of the stacks on said conveyor as the strap is fed into the said strap guide track, strapping means adjacent said strap guide track for withdrawing the strap from the strap guide track and tensioning it into a closed loop about said stack, a braking means on the conveyor for arresting the movement of the stacks of objects on the conveyor, a magnetic sensing means for causing the braking means to be actuated in response to the presence of a strap from a strapped stack, the magnetic sensing means being spaced forward of the strap guide track by an amount equal to said dimension of the stacks, said forward spacing of the magnetic sensing means insuring that the stack immediately following a stack just strapped is properly aligned for strapping adjacent the strap guide track when the braking ocurs due to magnetic sensing of the strap on the stack just strapped, said magnetic sensing means being mounted on the conveyor for movel a 15 ment transversely of the conveyor in response to force applied by a strapped stack moving along the conveyor.

21. A packaging machine comprising, conveyor means for movably supporting a plurality of closely positioned stacks in a row extending along the length of the conveyor, said stacks all having the same dimension in the direction of the row, a strap guide track on said conveyor positioned to guide a length of strap about one of the stacks on said conveyor as the strap is fed into the said strap guide track, strapping means adjacent said strap guide track for withdrawing the strap from the strap guide track and tensioning it into a closed loop about said stack, a braking means on the conveyor for arresting the movement of the stacks of objects on the conveyor, a magnetic sensing means for causing the braking means to be actuated in response to the presence of a strap from a strapped stack, the magnetic sensing means being spaced forward of the strap guide track by an amount equal to said dimension of the stacks, said forward spacing'ofthe magnetic sensing means insuring that the stack immediately following a stack just strapped is properly aligned for strapping adjacent the strap guide track when the braking occurs due to magnetic sensing of the strap on the stack just strapped, a gate pivoted on said conveyor between a position blocking the forward passage of the stacks on the conveyor and a position clear of their passage, said gate in its blocking position being spaced from the strap guide track location by a fixed amount for the purpose of establishing the location. of the first strap, to be applied on the leading a stack of the plurality of closely positioned stacks on the conveyor when they are all pushed up toward the gate with the leading stack in contact with it, said magnetic sensing means being mounted on the conveyor for movement transversely of the conveyor in response to force applied by a strapped stack moving along the conveyor.

7 22. A packaging machine comprising, conveyor means for movably supporting a plurality of stacks of objects in a row, a strap guide track on said conveyor positioned to guide a length of strap about one of the stacks on said conveyor as the strap is fed into the strap guide track, strapping means adjacent the strap guide track for withdrawing the strap from the strap guide track and tensioning it into a closed loop about said stack, braking means on the conveyor for arresting the movement of the stacks on the conveyor, and magnetic sensing means for causing the braking means to be actuated in response to the presence of a strap on a strapped stack, said magnetic sensing means being mounted on the conveyor for movement transversely of the conveyor in both transverse directions, the movement in one direction being caused by the contact of stacks moved along the conveyor, and the movement in the other'direction being urged by resilient means reacting between the conveyor frame and the ma netic sensing means, the urging of movement In the other direction causing the magnetic sensing means to closely V v V 16 contact the sides of the stacks as they the conveyor.

23. A packaging machine comprising, conveyor means for movably supporting a plurality of stacks of objects in a row, a strap guide track on said conveyor positioned to guide a length of strap about one of the stacks on said conveyor as the strap is fed into the strap guide track, strapping means adjacent thestrap guide traclcfor are moved along withdrawing the strap from the strap guide trackv and tensioning it into a closed loop about said stack, braking means on the conveyor for arresting'the mpvement of the stacks on the conveyor, and magnetic sensing means for causing the braking means to be actuated .in response to the presence of a strap on a strapped stack, said strapping means being supported above the path of travel on the conveyor of the stacks on resilient means which provides resilient movement of the strapping means both perpendicular to, the conveyor in horizontal planes and transversely to the conveyor.

24. The method of packaging objects com-prising piling them in vertical stacks and positioning the stacks in a row so that certain corners of the stacks are aligned longitudinally of the row, applying a leading portion of a flexible corner protector stn'p extending from a continuous supply of corner protector strip to said strip longitudinally aligned corners of the stacks, applying at least one strap around at least one, of said stacks to secure the corner protector strip to each stack and to hold each stack together as a unit pack of said objects, then transporting forward the stacksin thetrow to cause the stacks to which the corner protector strip is strapped to pull the continuous corner protector strip with them as they are transported forward to cause the strip to be drawn off from said continuous supply and applied continuously to corners of the unstrapped stacks in the row following the strapped stacks, and then applying additional straps around the unstrapped stacks to secure the corner pro tector strip to them and allow the portion of the corner protector strip secured to the strapped stacks to act as a connector between the strapped stacks. a

25. The method according to claim 24 characterized by,'and then lifting one or more of the forward strapped stacks in said row as a unit relative to the remaining stacks to cause the corner protector strip to be severed between said forward strapped stacks and those remaining. V

by, and then lifting the first of said stacks relative to the said next stack to cause the corner protector strip con nected between them to be severed.

References Cited in the file of this patent UNITED STATES PATENTS 2,616,361 Friesner s Nov. 4, 1952 2,664,813 Rose Jan. 5, 1954 2,844,091 Shafer July 22, 195

26. The'method according to claim 3 characterized UNITED STATES PATENT OFFICE CERTIFICATION OF CORRECTION Patent, No, $003,296 October 10, 1961 John G.- Feldkamp etal.

It is hereby certified that error appears in the above numbered pat-g ent requiring correction and that the said Letters Patent should read as corrected below. A

Column 3, line 66, after "removed" insert a comma; column 9 line 17, strike out "in the magnetic" first occurrel column 10" line 64, and column 11, line 22, for "apply", each occurrence, read applying column 12, line 17, after "occurs" insert due column 16, line 25 strike out "strip'fi, second occurrence.

Signed and sealed this 3rd day of April 1962.

Attest:

ERNEST W. SWIDER DAVID L. LADD Attesting Officer Commissioner of Patents 

